Hybrid grass pitches are known and have been used for some years. A significant number of hybrid grass pitches has now been laid. One well-known example is the grass pitch of Wembley Stadium in London. A hybrid grass pitch has various advantages over a natural grass pitch, and also various advantages over a fully artificial grass pitch.
One advantage of a hybrid grass surface over a natural grass surface is that the durability is greater. Up to twice as many hours of sport per year can be played on a hybrid grass pitch as on a natural grass pitch.
Another advantage over natural grass is that the grass pitch remains green at all times. In addition, less pollen are released on use. The artificial grass strands effectively act as reinforcement to the ground and retain the pollen in their location.
A further associated advantage is that the surface is stiffer and can better resist impact and can be used more easily for other activities such as a concert. This is because the roots of the grass strands grow through the artificial grass strands. In addition, a hybrid grass surface drains better because the injected artificial grass strands form vertical drainage channels.
An advantage of a hybrid surface over a fully artificial grass surface is that the majority of the grass strands are natural, including the associated properties which are relevant for walking, running and rolling a ball. Also, the fragrance of a hybrid grass pitch is the same as that of a natural grass pitch.
Previously, machines for creating hybrid grass pitches were developed and produced by the company Desseaux (now written as Desso). One such machine is described in WO2001/79611A1. In this machine, the artificial grass strands are carried by compressed air to below an insertion device.
EP1384817 describes another machine for creating hybrid grass surfaces. In this machine, a single artificial grass strand is wound in a helical pattern around a drum. Then the single strand is cut into a plurality of strands by means of a cutting device. The strands are then inserted in the ground with an insertion device.
The company Desso has also developed another machine for creating hybrid grass pitches, which has also been brought into use.
The present invention is based on the insight that the known machines are quite slow due to their design. In addition, the known machines are not fully reliable in the sense that the insertion of a significant proportion of the artificial grass strands fails, and this leads to wastage.